No Mercy
by Icestorm238
Summary: "You stare at the skeleton, his form blurred through the thick fog. He stands at ease; slouched over, hands shoved in pockets, a lazy grin on his face. He knows what you are - what you've done – but if you didn't already know you would never have guessed."
1. You're Gonna Have

**So I'm joining the Undertale fandom a little late, but here's a story set in the AU where you fight Sans in Snowdin instead of Papyrus, who you fight in the Last Corridor. Obviously, it's part of the genocide route.**

 **Thanks to WolfHowl091, because if she hadn't put up with my constant questions and doubts about this, it wouldn't be finished.**

* * *

"Hey kid."

You stare at the skeleton, his form blurred through the thick fog. He stands at ease; slouched over, hands shoved in pockets, a lazy grin on his face. He knows what you are - what you've done – but if you didn't already know you would never have guessed. His relaxed demeanour is unnerving, and you subconsciously tighten your grip on the handle of your knife.

He shuffles slightly, his slippers crunching through the snow. The sound is like a warm knife through butter as it cuts through the silence. "So, having fun?" he asks, voice jovial as always. "I guess you are, judging by the wide smile you've been wearing as you slaughter innocents." As your eyes widen, he smirks. "Oh yeah, I've been watching. I've seen every slash, stab and slice, every single monster in the nearby vicinity crumble to dust. You're leaving no stone unturned in your quest for LOVE, are you?"

He quietens for a moment, as if gathering his thoughts. You risk tearing your gaze from the bony figure to glance at the blade of your knife; it's coated in the dust of those whose lives you stole. He isn't wrong; you backtracked a couple dozen times just in case you missed a chance to gain more EXP. Your legs ache from trudging through mounds of snow and the knife feels like lead in your hand.

"It's happened too often now," the skeleton says, slapping you out of your thoughts and back to reality. You hastily draw your attention back to him, mentally berating yourself for your temporary loss of focus. "Over and over," he continues, seemingly not noticing your short distraction, "he dies. Time after time after time. I think after every reset, 'maybe this time will be different'. I hope and I pray, but to no avail."

"Every single time, you kill my brother."

Your hand clenches around the knife handle again as a feeling rises within you. It surely can't be guilt; it's far too late for that. You're much too far gone.

The skeleton hunches his shoulders. "It always plays out the same way. You come through the door, skip through my brother's puzzles, then reach this area. Every time, he appeals to your humanity." He let out a short bark of laughter. "My bro always sees the best in people. I don't know how he does it. It was his downfall with you, though. Every time, he spares you, and every time you murder him."

Your hand starts to shake and you find yourself unable to quell it. All you can do is hope he doesn't pick up on the tremor, on your weakness.

The skeleton's voice softens. "He believed in you," he says, his voice a mere whisper. You can barely hear his words over the howling wind. "He always believed in you, and you always struck him down without a care. Do you have any idea how I feel? Knowing what's coming, but being unable to do anything. The crushing feeling of hopelessness… I can't take it anymore. I can't lose him again."

"So here I am."

His eyes properly meet yours for the first time, the lights dulled with a never-ending grief. "I sent him off to help evacuate. He wanted to be here to fight you, but I wouldn't let him. He wasn't exactly happy, but I'd rather he be unhappy than dead."

He sighs loudly, as if tired of it all. "You'd think I'd learn from my brother's mistakes. You'd think I'd kill you before the monologue, before you had the chance to kill me first. I owe it to my bro to at least try, though, so…"

He removes his right hand from his pocket and holds it out towards you, palm up.

"I made a promise."

You stare at the skeleton, confused by the unexpected move. You watch the bony hand as it hovers invitingly. Suspecting a trick you stay alert, frozen fingers still tight around the knife's handle. His smile appears to, if anything, shift from menacing to comforting as he stands with arm outstretched.

"I promised," he continues, "that if a human walked through that door, I would spare them."

As he speaks you jerk your head up to look him in the eye once more. Why he would make such a promise is beyond you, when he remembers all that you've done. When he knows what you are.

"It doesn't have to be this way," he says quietly. "This can end, here and now. All you have to do is drop the knife. Put it on the floor and walk away. That's it. You can do that for me, right… friend?"

You stare, unmoving. He cannot be serious. After everything, all the murders you committed, all the EXP and LOVE you gained, there is absolutely no way he would offer you mercy.

It must be a trap.

Somehow though, even with that knowledge, you still find yourself considering it. How easy it would be to finally unclench your hand, to let the knife fall to land harmlessly in the snow. You would finally be free from this endless cycle of hate, destruction and death.

No.

If you accept his mercy, you will die.

You have no choice.

In one fluid motion you attack, arcing your knife in a downward slash aimed at the skeleton you once called a friend. He throws himself to the side, and you glimpse the sad smile he displays as your knife passes by harmlessly.

You spin, desperate to gain the upper hand. Moving faster than you ever have before, you throw your arm toward the sky, the knife cleanly scoring an incision up the back of his spine.

He staggers forward as the bone cracks and flakes, hand flying back instinctively to hold the wound you inflicted. He makes no sound, but he doesn't need to. You step back as he collapses face-first into the snow, no longer able to support himself. Still he remains silent, even as he forces his head up so he can support it with his free hand while escaping the face full of slush.

The silence is deafening as you stand there, just watching him. His position cannot be comfortable, folded in on himself like he is, but the damage you dealt to his spine renders him unable to move.

After what feels like an eternity of nothing, he laughs quietly, lacking the energy for anything louder. "I should have known it would end like this," he wheezes into the raging wind, rapidly losing the little strength he has left. "Why bother appealing to your humanity when you're just a demon in disguise?"

You force yourself not to react, not to show emotion.

"I warned you-"

He breaks off, hacking. Each cough causes more of his broken spine to splinter and fall off. "He won't forget this," he hisses. "I warned you. You're gonna have… a bad time..."

The skeleton's body pulses, converting into dust. As the bones crumble and the pile of dust gathers, you here one last word spoken into the wind.

"Papyrus…"

He is gone, leaving only his signature hoodie coated in golden dust.

You force down the rising wave of feelings, steeling yourself. You turn slowly, body aching, and walk numbly through the fog, away from the remains of your old friend, willing yourself not to care.

You don't need Sans watching over you, judging your every move.

You judge yourself enough for both of you.


	2. A Bad Time

**And here's part two!**

* * *

At first he appears as a shadow at the end of the corridor. You stumble along, covered in a mixture of your own blood and monster dust, and he comes into focus. Standing tall, a familiar hoodie wrapped around his hips, he waits patiently for you to approach. You haven't seen him since before you killed his brother, when he looked at you with wide-eyes and smiles, full of hope. Now all you can see is a hatred he doesn't even attempt to conceal. You search your soul for something – remorse, pity, loathing – but find nothing. You're empty inside.

"I've been waiting for you," the skeleton says as you come to a stop before him, his voice more muted than you remember. "You took your time. Of course, you couldn't pass up the chance for some casual murder, could you? You had to kill all you could."

There is nothing you can say. You have no excuse for your actions. You have no real desire to defend yourself anyway. You slide your leg backwards, turning your body sideways and raising the knife you grip in your dominant hand; your combat stance. Throughout this process you keep your gaze locked with his, refusing to break eye contact.

"So that's how it is." He chuckles humourlessly, raising his arm in an action that parallels his brother's earlier offer of mercy. "You're not even going to let me talk. Very well, human, if that's what you want..."

Quickly, so very quickly, before you can even register the movement, a bone pulsating with a blue light forms in his hand. He flicks his wrist sharply, the bone flying towards you. It smacks straight into your chest, melting into your soul. You feel the new, yet somehow familiar weight settle as you gasp, free hand flying to press against the entry point.

The skeleton gives you a cold smirk and throws his arm to the left. Your soul follows his hand, sending you crashing into a pillar. Groaning, you force yourself into a sitting position to find a cage of bones surrounding you. When you attempt to stand one jabs you sharply in the neck, causing you to hiss in pain.

"…then I'll have to restrain you while I monologue," he says, finishing the sentence you hadn't even realised was incomplete. "I learnt from my brother's mistakes," he continues. "I'm not going to just let you stand there, free to attack at any moment. I will say my piece, whether you like it or not."

You cough, feeling a painful stab as you do so. You must have broken a rib or two on impact with the pillar. It doesn't matter; you're used to battling through pain. You just need to escape from the prison that holds you captive so that you can fight him.

"I won't pretend to fully understand your powers," he says after a pause, hand hovering in front of him as he pours his energy into controlling the bones. "My brother only explained a little to me, and even that was rushed and incoherent. I gathered the basics, though; multiple timelines, the ability to save, load, and reset… a power which you abused."

You tilt your head back to rest it against the pillar, making sure to maintain eye contact with the skeleton. You show no other reaction to his accusation, simply content to let him talk for now. You can do little else, surrounded as you are.

He hesitates for a moment, choosing his next words carefully. "I remember things," he continues. "Pain, mostly, and the occasional memory through my dreams. I never understood the significance of them, but I remember."

The bones waver slightly. "My brother understood. He remembered everything; my many deaths, our friends' deaths, and the agony of his own deaths. He remembered it all in excruciating detail." He chuckles humourlessly. "I thought he was just lazy, but I know the whole story now. He'd seen it all happen so many times he'd just stopped caring, choosing apathy over anguish. Now that I know the truth, I don't blame him at all."

A couple of the bones flicker, fazing in and out of existence. He doesn't seem to notice, caught up in the thoughts he is spilling to you. "I regret it. Every time I nagged him to stop being so lazy, thinking he was just being annoying, when in reality he was suffering so much for so long."

He narrows his eyes. "You caused that. Every time you reset, you caused him more pain."

"I despise you."

Now. The circle of bones has broken. Only a few remain in position, the others having dissolved into nothingness. Ignoring the sharp flare of agony in your sides you quickly force yourself onto your feet, racing towards the distracted skeleton, blade raised in anticipation.

Ah. He isn't completely lost in his regrets after all. He has enough awareness of his surroundings to throw himself to the side, avoiding your strike. Out of the corner of your eye you notice the other bones join their comrades in non-existence as he releases his control over them, instead summoning a large femur. Dual-wielding the bone as if it were a sword, he swings it horizontally towards you, all before landing after his dodge. You cry out as it smashes into your side, crashing into your already-damaged ribs. You hit the far wall hard, head cracking against it painfully, knife falling from your hand and clattering to the floor. Blood trickles from your head down your face, some entering your eyes and blurring your vision. Blinking rapidly, you attempt to push yourself up, but your arms collapse and you fall back to the ground.

"Did you really think it would be that easy?" he asks. "I'm disappointed, truth be told. That," he gestures to you with the femur, "was actually quite pathetic."

You grit your teeth, once again trying to rise, and once again flopping like a seal. The humiliation of the situation washes over you like a tidal wave. You are at the skeleton's mercy; not that you expect any from him at this point.

Through the agonizing pain you are experiencing you manage a bitter laugh. Out of everyone you've faced, you're lying helpless on the floor in front of this person; the spaghetti loving, ineffectual dork.

Or not, you muse thoughtfully. He's isn't much of a dork anymore, his hands glowing bright with magic as he holds the massive femur tightly, pulsating with hatred, rage and grief, no longer smiling, no longer loving. You've changed him, you realise, from a happy, caring person to this vengeful monster. You suppose you should feel bad about that, but you lost your emotions long ago. You don't really care.

He snaps the femur in two as if it were a twig, holding half in each hand. Opening one fist, he lets the bone drop. Before it hits the ground it disappears, no longer needed. The skeleton raises the remaining half and holds it steady in front of him, the jagged edge looking sharp enough to messily pierce through your organs.

As he approaches you let your head drop. It's taking too much effort to keep it raised, and you don't want to watch him anymore. You're too tired. You stare at the patterned tiles stained red with your blood, listening to the steps he takes ring out your death sentence.

"Not even going to fight back?" he sneers. "Pitiful." His bones creak as he lifts the femur, not that you can see his movements anymore. So this will be your first death of this run. It's a shame – you had hoped to win with no deaths.

As you lie still on the cold tiles you tilt your head slightly to the right, unintentionally coating your hair with more blood. Your knife gleams, a beam of light filtering into the hall through one of the enormous windows and bouncing off the metal. It is tantalisingly just out of reach. If only you could grab it, you might not have to die.

As the thought enters your mind you feel a rush of adrenaline. You could reach it. If you jerk yourself to the side, you could-

A whoosh from above alerts you to the downward arc of the femur. No more time to think. You act, using whatever strength you have left to twist yourself sideways. Your body screams in agony but your hand successfully closes around the hilt. The skeleton shouts in surprise as his weapons clanks loudly against the floor. Determined, you force yourself up with aching arms, managing to stand on shaky legs. He is just recovering, spinning to face you while dragging the bone back up into a defensive position. Before he can complete the motion you lunge forward, letting out a primal howl of pain. You slice your weapon through the air just as he gets the femur into place. The steel cuts through his vertebrae just below his head at the exact same time as the jagged ends of his weapon pierces your chest just below your heart.

You stare at each other, shock etched on your faces. He begins to collapse in front of your eyes, head sliding from its perch to the floor. It doesn't even make it, body dissolving into dust first. The femur fades from existence, leaving a gaping hole in your body. Stumbling backwards you bump into the pillar, slowly sliding down as you press against the wound with both hands. The knife falls to the ground with a clatter, forgotten. Blood is gushing out of your chest, painting your hands red and causing a rising wave of nausea. The injury is deep. The bone almost penetrated through your back. There's no way you can survive this.

You will die.

Tilting your head back, mirroring your previous actions, you begin to laugh. It starts quiet, and then gains in volume, ferocity and madness. You don't know what exactly you're finding funny, you just laugh.

This slow, painful death must be your punishment. Your gaze falls onto the blue hoodie and red scarf, lying in a bundle on the floor, coated in two separate monsters' dust. Your laughter intensifies unwillingly.

Maybe you won't reload this time. Maybe you'll reset, start over, set things right. Maybe you'll leave things as they are. You'll decide later, after you've died.

At least Sans and Papyrus are together in the afterlife.

You won't be joining them there.

You die with a wide smile on your face.


End file.
